Event
BIOE Seminar: Sarah Glaven
Friday, September 13, 2019
9:00 a.m.-10:00 a.m.
A. James Clark Hall, Room 2132
Emily Rosenthal
301 405 3936
erosent1@umd.edu
Dr. Sarah Glaven
Research Biologist
Naval Research Laboratory
Electromicrobiology: from field to technology, and back again
Electroactive (EA) bacteria exchange electrons with an electrode by extracellular electron transfer (EET) for growth and survival. EA bacteria are found almost everywhere someone has looked; from the bottom of the ocean to the human gut microbiome. The ability to rationally engineer EET processes will result in technological advancements for biomaterials including microbial electrosynthesis, conducting polymers, and microbial bioelectronics. These technologies are currently limited by proper and predictable expression and orientation of electron transfer proteins in the cell membrane, the ability to rapidly screen a large number of synthetic constructs for EET, and a library of operationally relevant chassis strains and electron transfer parts. In this talk, I will describe development of a synthetic biology toolkit by our lab group for EET in operationally relevant chassis strains, such as those that can live in highly saline environments, or grow by CO2 fixation and energy from an electrode. We show that using a suite of highly-optimized small molecule sensors, we can activate EET in the marine bacterium, Marinobacter atlanticus, through expression of the Shewanella electron transfer conduit. We found that the key design rule for engineering EET was increased expression of the native cytochrome c maturation system, which also boosted innate EET. We also built a custom electrochemical flow cell to temporally assess inducible protein expression in biofilms of electroactive bacteria. Leveraging these tools, we attempted in situ transformation of the syntroph-dependent electroautotroph “Ca. Tenderia electrophaga”. We utilized a suite of broad host range vectors harboring ampicillin resistance to directly transform electrode biofilms. Electrical current was observed within 24 hours in the presence of antibiotics, indicating “Ca. Tenderia electrophaga” was likely transformed.These efforts will enable development of engineered, self-healing living bioelectronic materials, as well as materials synthesis from gas and electrodes, specifically under austere conditions, such as the ocean, the International Space Station, or even other planets.
Dr. Glaven is a research biologist at the U.S. Naval Research Laboratory (NRL) with over 12 years of experience in the field of microbial electrochemistry and electromicrobiology, processes in which microorganisms are used to catalyze electrode reactions and transport electrons over micron-scale distances. Dr. Glaven is recognized worldwide as an expert in this field and for her recent work using meta-omics to understand electron transfer and carbon fixation in electroautotrophic biofilm communities. More recently, Dr. Glaven has begun incorporating tools and practices of synthetic biology in her research to engineer extracellular electron transfer (EET). During the summer, she mentors undergraduates from the U.S. Naval Academy to compete in the International competition of Genetically Engineered Machines (iGEM). She currently serves on the editorial board of the new journal Biofilms and mSystems and is the current President of the International Society for Microbial Electrochemistry and Technology (ISMET).
